Contact: Karen Richardson
Wake Forest Baptist Medical Center
Research in rodents suggests potential for ‘in body’ muscle
Winston-Salem, N.C. – Sept. 2, 2014 – What if repairing large
segments of damaged muscle tissue was as simple as mobilizing the
body’s stem cells to the site of the injury? New research in mice
and rats, conducted at Wake Forest Baptist Medical Center’s
Institute for Regenerative Medicine, suggests that “in body”
regeneration of muscle tissue might be possible by harnessing the
body’s natural healing powers.
Reporting online ahead of print in the journal Acta Biomaterialia,
the research team demonstrated the ability to recruit stem cells
that can form muscle tissue to a small piece of biomaterial, or
scaffold that had been implanted in the animals’ leg muscle. The
secret to success was using proteins involved in cell communication
and muscle formation to mobilize the cells.
“Working to leverage the body’s own regenerative properties, we
designed a muscle-specific scaffolding system that can actively
participate in functional tissue regeneration,” said Sang Jin Lee,
Ph.D., assistant professor of regenerative medicine and senior
author. “This is a proof-of-concept study that we hope can one day
be applied to human patients.”
The current treatment for restoring function when large segments of
muscle are injured or removed during tumor surgery is to surgically
move a segment of muscle from one part of the body to another. Of
course, this reduces function at the donor site.
Several scientific teams are currently working to engineer
replacement muscle in the lab by taking small biopsies of muscle
tissue, expanding the cells in the lab, and placing them on
scaffolds for later implantation. This approach requires a biopsy
and the challenge of standardizing the cells.
“Our aim was to bypass the challenges of both of these techniques
and to demonstrate the mobilization of muscle cells to a target-
specific site for muscle regeneration,” said Lee.
Most tissues in the body contain tissue-specific stem cells that
are believed to be the “regenerative machinery” responsible for
tissue maintenance. It was these cells, known as satellite or
progenitor cells, that the scientists wanted to mobilize.
First, the Wake Forest Baptist scientists investigated whether
muscle progenitor cells could be mobilized into an implanted
scaffold, which basically serves as a “home” for the cells to grow
and develop. Scaffolds were implanted in the lower leg muscle of
rats and retrieved for examination after several weeks.
Lab testing revealed that the scaffolds contained muscle satellite
cells as well as stem cells that could be differentiated into
muscle cells in the lab. In addition, the scaffold had developed a
network of blood vessels, with mature vessels forming four weeks
Next, the scientists tested the effects of several proteins known
to be involved in muscle formation by designing the scaffolds to
release these proteins. The protein with the greatest effect on
cell recruitment was insulin-like growth factor 1 (IGF-1).
After several weeks of implantation, lab testing showed that the
scaffolds with IGF-1 had up to four times the number of cells than
the plain scaffolds and also had increased formation of muscle
“The protein effectively promoted cell recruitment and accelerated
muscle regeneration,” said Lee.
Next, the scientists will evaluate whether the regenerated muscle
is able to restore function and will test clinical feasibility in a
large animal model.
The research was supported by the Armed Forces Institute of
Regenerative Medicine, a federally funded effort to apply
regenerative medicine to battlefield injuries.
Co-researchers were: Young Min Ju, Ph.D., lead author, Anthony
Atala, M.D., and James J. Yoo, M.D., Ph.D., all with the Institute
for Regenerative Medicine.
Media Contacts: Karen Richardson, firstname.lastname@example.org, (336)
716-4453) or Main Number (336) 716-4587.
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